Community-based strategies to increase coverage of intermittent preventive treatment of malaria in pregnancy with sulfadoxine-pyrimethamine in sub-Saharan Africa: a systematic review, meta-analysis, meta-ethnography, and economic assessment.

BACKGROUND: Community-based approaches might increase uptake of intermittent preventive treatment of malaria in pregnancy with sulfadoxine-pyrimethamine (IPTp-SP). We assessed the effects of community-based approaches on IPTp-SP and antenatal care coverage, and barriers and facilitators to implementation in sub-Saharan Africa. METHODS: We did a systematic review, meta-analysis, meta-ethnography, and economic assessment. We searched the WHO International Clinical Trials Registry Platform, PubMed, the Malaria in Pregnancy Library database, Medline, Global Health and Global Health Archives, and the Cochrane Library for trials, mixed-methods, qualitative, and cost-effectiveness studies of community health worker promotion of antenatal care, IPTp-SP delivery, or both, with no language restrictions, published before March 21, 2024. Information on interventions, number of IPTp-SP doses, antenatal care visits, and barriers and facilitators were extracted. We did a meta-analysis (random effects) comparing effects on two or more or three or more IPTp-SP doses and one or more or four or more antenatal care visits. We followed Noblit and Hare's method of meta-ethnography to synthesise qualitative findings, using reciprocal translation and line-of-argument synthesis. We developed a theory for increased community IPTp-SP uptake. We also summarised cost and cost-effectiveness studies. This study is registered with PROSPERO, CRD42022364114. FINDINGS: Of 4753 records screened, we included 23 (0·5%) reporting on 15 studies. Community health worker involvement was associated with an increase in two or more IPTp-SP doses (pooled risk ratio 1·48, [95% CI 1·24-1·75]; 12 sub-studies; I2 94·7%) and three or more IPTp-SP doses (1·73 [1·19-2·50]; ten sub-studies, I2 97·5%), with no decrease in four or more antenatal care visits (1·17 [1·00-1·36]; 13 sub-studies; I2 90·3%). Cluster-randomised controlled trials showed a lower increase in coverage of three or more IPTp-SP doses (1·08 [1·00-1·16]; I2 0·0%; six studies) compared with before-and-after studies (2·86 [1·29-6·33]; I2 98·9%; four studies; subgroup analysis p=0·019). Barriers to community health worker delivery of IPTp-SP included women's fear of side-effects, lack of knowledge, lack of trust in community health workers, and sociocultural factors. Community sensitisation, engagement of husbands, pre-established community health worker networks, and trained and supported community health workers facilitated IPTp-SP delivery by community health workers. Incremental cost-effectiveness ratios ranged from $1·1 to $543 per disability-adjusted life-year averted. INTERPRETATION: Community-based approaches increased IPTp-SP coverage and might have a positive effect on the number of antenatal care visits in addition to being cost-effective, although we found high heterogeneity among studies. Community sensitisation and engagement in addition to established, trained, and supported community health workers can facilitate acceptability, delivery, and uptake of IPTp-SP delivered by community health workers. FUNDING: EDCTP-2 supported by the European Union. TRANSLATION: For the French translation of the abstract see Supplementary Materials section.

Community case management to accelerate access to healthcare in Mali: A realist process evaluation nested within a cluster randomised trial.

The Proactive Community Case Management (ProCCM) trial in Mali reinforced the health system across both arms with user fee removal, professional Community Health Workers (CHWs), and upgraded primary health centres (PHCs)-and randomized village-clusters to receive proactive home visits by CHWs (intervention) or fixed site-based services by passive CHWs (control). Across both arms, sick children's 24-hour treatment and pregnant women's four or more antenatal visits doubled, and under-five mortality halved, over three years compared to baseline. In the intervention arm, proactive CHW home visits had modest effects on children's curative and women's antenatal care utilization, but no effect on under-five mortality, compared to the control arm. We aimed to explain these results by examining implementation, mechanisms, and context in both arms. We conducted a process evaluation with a mixed method convergent design that included 79 in-depth interviews with providers and participants over two time-points, surveys with 195 providers, and secondary analyses of clinical data. We embedded realist approaches in novel ways to test, refine, and consolidate theories about how ProCCM worked, generating three context-intervention-actor-mechanism-outcome nodes that unfolded in a cascade. First, removing user fees and deploying professional CHWs in every cluster enabled participants to seek health sector care promptly and created a context of facilitated access. Second, health systems support to all CHWs and PHCs enabled equitable, respectful, quality healthcare, which motivated increased, rapid utilization. Third, proactive CHW home visits facilitated CHWs and participants to deliver and seek care, and build relationships, trust, and expectations, but these mechanisms were also activated in both arms. Addressing multiple structural barriers to care, user fee removal, professional CHWs, and upgraded clinics interacted with providers' and patients' agency to achieve rapid care and child survival in both arms. Proactive home visits expedited or compounded mechanisms that were activated and changed the context across arms.

Natural malaria infection elicits rare but potent neutralizing antibodies to the blood-stage antigen RH5.

Plasmodium falciparum reticulocyte-binding protein homolog 5 (RH5) is the most advanced blood-stage malaria vaccine candidate and is being evaluated for efficacy in endemic regions, emphasizing the need to study the underlying antibody response to RH5 during natural infection, which could augment or counteract responses to vaccination. Here, we found that RH5-reactive B cells were rare, and circulating immunoglobulin G (IgG) responses to RH5 were short-lived in malaria-exposed Malian individuals, despite repeated infections over multiple years. RH5-specific monoclonal antibodies isolated from eight malaria-exposed individuals mostly targeted non-neutralizing epitopes, in contrast to antibodies isolated from five RH5-vaccinated, malaria-naive UK individuals. However, MAD8-151 and MAD8-502, isolated from two malaria-exposed Malian individuals, were among the most potent neutralizers out of 186 antibodies from both cohorts and targeted the same epitopes as the most potent vaccine-induced antibodies. These results suggest that natural malaria infection may boost RH5-vaccine-induced responses and provide a clear strategy for the development of next-generation RH5 vaccines.

Autoantibodies inhibit Plasmodium falciparum growth and are associated with protection from clinical malaria.

Many infections, including malaria, are associated with an increase in autoantibodies (AAbs). Prior studies have reported an association between genetic markers of susceptibility to autoimmune disease and resistance to malaria, but the underlying mechanisms are unclear. Here, we performed a longitudinal study of children and adults (n = 602) in Mali and found that high levels of plasma AAbs before the malaria season independently predicted a reduced risk of clinical malaria in children during the ensuing malaria season. Baseline AAb seroprevalence increased with age and asymptomatic Plasmodium falciparum infection. We found that AAbs purified from the plasma of protected individuals inhibit the growth of blood-stage parasites and bind P. falciparum proteins that mediate parasite invasion. Protected individuals had higher plasma immunoglobulin G (IgG) reactivity against 33 of the 123 antigens assessed in an autoantigen microarray. This study provides evidence in support of the hypothesis that a propensity toward autoimmunity offers a survival advantage against malaria.

Assessment of the impact of pregnancy and malaria infection on the variation of neutrophil levels in women from San, Mali.

BACKGROUND: In patients with severe neutropenia, infections can rapidly become serious and life-threatening. It is essential to understand whether pregnancy induces changes in neutrophil levels thereby posing an increased threat to the health of gravidae. METHODOLOGY: This cross-sectional study was conducted in San Health District (Mali) and involved pregnant women infected or not by malaria parasites and non-pregnant healthy volunteers. Subjects were categorized as having neutropenia, normal neutrophil levels, and neutrophilia regarding their neutrophil levels. A logistic regression analysis was performed to determine factors associated with neutrophil level variation in pregnant women. RESULTS: Whether or not the pregnant women were infected with malaria, 98 of the 202 cases (48.5%) showed neutrophilia. Surprisingly, 67 of the 71 cases of neutropenia (94.4%) observed in this study concerned healthy people who were not pregnant. The mean percentage of neutrophil levels was significantly (p < 0.001) lower (49.9%) in the first trimester compared to the second trimester of pregnancy (62.0%). A logistic regression model showed that compared to early pregnancy, the second (OR = 12.9, 95% CI 2.2-248.1, p = 0.018) and the third trimesters (OR = 13.7, 95% CI 2.3-257.5, p = 0.016) were strongly associated with the increase of neutrophil levels. CONCLUSIONS: Pregnancy can induce the production of mature neutrophils that are continually released into circulation. Neutrophil levels were lower during the first trimester of the pregnancy compared to the second and third trimesters, but not affected by the presence or absence of malaria infection.

Factors influencing pregnancy care and institutional delivery in rural Mali: a secondary baseline analysis of a cluster-randomised trial.

OBJECTIVE: The vast majority of the 300 000 pregnancy-related deaths every year occur in South Asia and sub-Saharan Africa. Increased access to quality antepartum and intrapartum care can reduce pregnancy-related morbidity and mortality worldwide. We used a population-based cross-sectional cohort design to: (1) examine the sociodemographic risk factors and structural barriers associated with pregnancy care-seeking and institutional delivery, and (2) investigate the influence of residential distance to the nearest primary health facility in a rural population in Mali. METHODS: A baseline household survey of Malian women aged 15-49 years was conducted between December 2016 and January 2017, and those who delivereda baby in the 5 years preceding the survey were included. This study leverages the baseline survey data from a cluster-randomised controlled trial to conduct a secondary analysis. The outcomes were percentage of women who received any antenatal care (ANC) and institutional delivery; total number of ANC visits; four or more ANC visits; first ANC visit in the first trimester. RESULTS: Of the 8575 women in the study, two-thirds received any ANC in their last pregnancy, one in 10 had four or more ANC visits and among those that received any ANC, about one-quarter received it in the first trimester. For every kilometre increase in distance to the nearest facility, the likelihood of the outcomes reduced by 5 percentage points (0.95; 95% CI 0.91 to 0.98) for any ANC; 4 percentage points (0.96; 95% CI 0.94 to 0.98) for an additional ANC visit; 10 percentage points (0.90; 95% CI 0.86 to 0.95) for four or more ANC visits; 6 percentage points (0.94; 95% CI 0.94 to 0.98) for first ANC in the first trimester. In addition, there was a 35 percentage points (0.65; 95% CI 0.56 to 0.76) decrease in likelihood of institutional delivery if the residence was within 6.5 km to the nearest facility, beyond which there was no association with the place of delivery. We also found evidence of increase in likelihood of receiving any ANC care and its intensity increased with having some education or owning a business. CONCLUSION: The findings suggest that education, occupation and distance are important determinants of pregnancy and delivery care in a rural Malian context. TRIAL REGISTRATION NUMBER: NCT02694055.

Susceptibility to febrile malaria is associated with an inflammatory gut microbiome.

Malaria is a major public health problem, but many of the factors underlying the pathogenesis of this disease are not well understood. Here, we demonstrate in Malian children that susceptibility to febrile malaria following infection with Plasmodium falciparum is associated with the composition of the gut microbiome prior to the malaria season. Gnotobiotic mice colonized with the fecal samples of malaria-susceptible children had a significantly higher parasite burden following Plasmodium infection compared to gnotobiotic mice colonized with the fecal samples of malaria-resistant children. The fecal microbiome of the susceptible children was enriched for bacteria associated with inflammation, mucin degradation, gut permeability and inflammatory bowel disorders (e.g., Ruminococcus gauvreauii, Ruminococcus torques, Dorea formicigenerans, Dorea longicatena, Lachnoclostridium phocaeense and Lachnoclostridium sp. YL32). However, the susceptible children also had a greater abundance of bacteria known to produce anti-inflammatory short-chain fatty acids and those associated with favorable prognosis and remission following dysbiotic intestinal events (e.g., Anaerobutyricum hallii, Blautia producta and Sellimonas intestinalis). Metabolomics analysis of the human fecal samples corroborated the existence of inflammatory and recovery-associated features within the gut microbiome of the susceptible children. There was an enrichment of nitric oxide-derived DNA adducts (deoxyinosine and deoxyuridine) and long-chain fatty acids, the absorption of which has been shown to be inhibited by inflamed intestinal epithelial cells, and a decrease in the abundance of mucus phospholipids. Nevertheless, there were also increased levels of pseudouridine and hypoxanthine, which have been shown to be regulated in response to cellular stress and to promote recovery following injury or hypoxia. Overall, these results indicate that the gut microbiome may contribute malaria pathogenesis and suggest that therapies targeting intestinal inflammation could decrease malaria susceptibility.

Subcutaneous Administration of a Monoclonal Antibody to Prevent Malaria.

BACKGROUND: Subcutaneous administration of the monoclonal antibody L9LS protected adults against controlled Plasmodium falciparum infection in a phase 1 trial. Whether a monoclonal antibody administered subcutaneously can protect children from P. falciparum infection in a region where this organism is endemic is unclear. METHODS: We conducted a phase 2 trial in Mali to assess the safety and efficacy of subcutaneous administration of L9LS in children 6 to 10 years of age over a 6-month malaria season. In part A of the trial, safety was assessed at three dose levels in adults, followed by assessment at two dose levels in children. In part B of the trial, children were randomly assigned, in a 1:1:1 ratio, to receive 150 mg of L9LS, 300 mg of L9LS, or placebo. The primary efficacy end point, assessed in a time-to-event analysis, was the first P. falciparum infection, as detected on blood smear performed at least every 2 weeks for 24 weeks. A secondary efficacy end point was the first episode of clinical malaria, as assessed in a time-to-event analysis. RESULTS: No safety concerns were identified in the dose-escalation part of the trial (part A). In part B, 225 children underwent randomization, with 75 children assigned to each group. No safety concerns were identified in part B. P. falciparum infection occurred in 36 participants (48%) in the 150-mg group, in 30 (40%) in the 300-mg group, and in 61 (81%) in the placebo group. The efficacy of L9LS against P. falciparum infection, as compared with placebo, was 66% (adjusted confidence interval [95% CI], 45 to 79) with the 150-mg dose and 70% (adjusted 95% CI, 50 to 82) with the 300-mg dose (P<0.001 for both comparisons). Efficacy against clinical malaria was 67% (adjusted 95% CI, 39 to 82) with the 150-mg dose and 77% (adjusted 95% CI, 55 to 89) with the 300-mg dose (P<0.001 for both comparisons). CONCLUSIONS: Subcutaneous administration of L9LS to children was protective against P. falciparum infection and clinical malaria over a period of 6 months. (Funded by the National Institute of Allergy and Infectious Diseases; ClinicalTrials.gov number, NCT05304611.).

Development and validation of an ultra-performance liquid chromatography-tandem mass spectrometry method for the quantification of the antimalarial drug pyronaridine in human whole blood.

Malaria remains a major health concern, aggravated by emerging resistance of the parasite to existing treatments. The World Health Organization recently endorsed the use of artesunate-pyronaridine to treat uncomplicated malaria. However, there is a lack of clinical pharmacokinetic (PK) data of pyronaridine, particularly in special populations such as children and pregnant women. Existing methods for the quantification of pyronaridine in biological matrices to support PK studies exhibit several drawbacks. These include limited sensitivity, a large sample volume required, and extensive analysis time. To overcome these limitations, an ultra-performance reversed-phase liquid chromatography tandem-mass spectrometry method to determine pyronaridine was developed and validated according to international guidelines. The method enabled fast and accurate quantification of pyronaridine in whole blood across a clinically relevant concentration range of 0.500-500 ng/mL (r2 ≥ 0.9963), with a required sample volume of 50 µL. Pyronaridine was extracted from whole blood using liquid-liquid extraction, effectively eliminating the matrix effect and preventing ion enhancement or suppression. The method achieved a satisfactory reproducible sample preparation recovery of 77%, accuracy (as bias) and precision were within ±8.2% and ≤5.3%, respectively. Stability experiments demonstrated that pyronaridine was stable for up to 315 days when stored at -70°C. Adjustments to the chromatographic system substantially reduced carry-over and improved sensitivity compared to prior methods. The method was successfully applied to quantify pyronaridine in whole blood samples from a selection of pregnant malaria patients participating in the PYRAPREG clinical trial (PACTR202011812241529) in the Democratic Republic of the Congo, demonstrating its suitability to support future PK studies. Furthermore, the enhanced sensitivity allows for the determination of pyronaridine up to 42 days post-treatment initiation, enabling assessment of the terminal elimination half-life.

Prevalence and factors associated with maternal and neonatal sepsis in sub-Saharan Africa: a systematic review and meta-analysis.

Objectives: This study aimed to determine the prevalence and factors associated with maternal and neonatal sepsis in sub-Saharan Africa. Methods: This systematic review and meta-analysis used the PRISMA guideline on sepsis data in sub-Saharan Africa. The bibliographic search was carried out on the following databases: Medline/PubMed, Cochrane Library, African Index Medicus, and Google Scholar. Additionally, the reference lists of the included studies were screened for potentially relevant studies. The last search was conducted on 15 October 2022. The Joanna Briggs Institute quality assessment checklist was applied for critical appraisal. Estimates of the prevalence of maternal and neonatal sepsis were pooled using a random-effects meta-analysis model. Heterogeneity between studies was estimated using the Q statistic and the I2 statistic. The funnel plot and Egger's regression test were used to assess the publication bias. Results: A total of 39 studies were included in our review: 32 studies on neonatal sepsis and 7 studies on maternal sepsis. The overall pooled prevalence of maternal and neonatal sepsis in Sub-Saharan Africa was 19.21% (95% CI, 11.46-26.97) and 36.02% (CI: 26.68-45.36), respectively. The meta-analyses revealed that Apgar score < 7 (OR: 2.4, 95% CI: 1.6-3.5), meconium in the amniotic fluid (OR: 2.9, 95% CI: 1.8-4.5), prolonged rupture of membranes >12 h (OR: 2.8, 95% CI: 1.9-4.1), male sex (OR: 1.2, 95% CI: 1.1-1.4), intrapartum fever (OR: 2.4, 95% CI: 1.5-3.7), and history of urinary tract infection in the mother (OR: 2.7, 95% CI: 1.4-5.2) are factors associated with neonatal sepsis. Rural residence (OR: 2.3, 95% CI: 1.01-10.9), parity (OR: 0.5, 95% CI: 0.3-0.7), prolonged labor (OR: 3.4, 95% CI: 1.6-6.9), and multiple digital vaginal examinations (OR: 4.4, 95% CI: 1.3-14.3) were significantly associated with maternal sepsis. Conclusion: The prevalence of maternal and neonatal sepsis was high in sub-Saharan Africa. Multiple factors associated with neonatal and maternal sepsis were identified. These factors could help in the prevention and development of strategies to combat maternal and neonatal sepsis. Given the high risk of bias and high heterogeneity, further high-quality research is needed in the sub-Saharan African context, including a meta-analysis of individual data.Systematic review registration: PROSPERO (ID: CRD42022382050).

Increasing the uptake of Intermittent Preventive Treatment of malaria in pregnancy using Sulfadoxine-Pyrimethamine (IPTp-SP) through seasonal malaria chemoprevention channel delivery: protocol of a multicenter cluster randomized implementation trial in Mali and Burkina Faso.

BACKGROUND: The uptake of Intermittent Preventive Treatment of malaria in pregnancy using Sulfadoxine-Pyrimethamine (IPTp-SP) remains unacceptably low, with more than two-thirds of pregnant women in sub-Saharan Africa still not accessing the three or more doses recommended by the World Health Organisation (WHO). In contrast, the coverage of Seasonal Malaria Chemoprevention (SMC), a more recent strategy recommended by the WHO for malaria prevention in children under five years living in Sahelian countries with seasonal transmission, including Mali and Burkina-Faso, is high (up to 90%). We hypothesized that IPTp-SP delivery to pregnant women through SMC alongside antenatal care (ANC) will increase IPTp-SP coverage, boost ANC attendance, and increase public health impact. This protocol describes the approach to assess acceptability, feasibility, effectiveness, and cost-effectiveness of the integrated strategy. METHODS AND ANALYSIS: This is a multicentre, cluster-randomized, implementation trial of IPTp-SP delivery through ANC + SMC vs ANC alone in 40 health facilities and their catchment populations (20 clusters per arm). The intervention will consist of monthly administration of IPTp-SP through four monthly rounds of SMC during the malaria transmission season (July to October), for two consecutive years. Effectiveness of the strategy to increase coverage of three or more doses of IPTp-SP (IPTp3 +) will be assessed using household surveys and ANC exit interviews. Statistical analysis of IPT3 + and four or more ANC uptake will use a generalized linear mixed model. Feasibility and acceptability will be assessed through in-depth interviews and focus group discussions with health workers, pregnant women, and women with a child < 12 months. DISCUSSION: This multicentre cluster randomized implementation trial powered to detect a 45% and 22% increase in IPTp-SP3 + uptake in Mali and Burkina-Faso, respectively, will generate evidence on the feasibility, acceptability, effectiveness, and cost-effectiveness of IPTp-SP delivered through the ANC + SMC channel. The intervention is designed to facilitate scalability and translation into policy by leveraging existing resources, while strengthening local capacities in research, health, and community institutions. Findings will inform the local national malaria control policies. TRIAL REGISTRATION: Retrospectively registered on August 11th, 2022; registration # PACTR202208844472053. Protocol v4.0 dated September 04, 2023. Trail sponsor: University of Sciences Techniques and Technologies of Bamako (USTTB), Mali.

Performance of ultra-sensitive malaria rapid diagnostic test to detect Plasmodium falciparum infection in pregnant women in Kinshasa, the Democratic Republic of the Congo.

BACKGROUND: Low peripheral parasitaemia caused by sequestration of Plasmodium falciparum in the placenta hampers the diagnosis of malaria in pregnant women, leading to microscopy or conventional rapid diagnostic tests (RDTs) false-negative results. Although mainly asymptomatic, maternal malaria remains harmful to pregnant women and their offspring in endemic settings and must be adequately diagnosed. Ultra-sensitive RDTs (uRDTs) are thought to be more sensitive than RDTs, and their diagnostic performance was assessed in the current study in pregnant women living in Kinshasa, a stable malaria transmission area in the Democratic Republic of the Congo. METHODS: To assess and compare the diagnostic performances of both RDTs and uRDTs, 497 peripheral blood samples were tested using microscopy and quantitative polymerase chain reaction (qPCR) as the index and the reference tests, respectively. The agreement between the different diagnostic tests assessed was estimated by Cohen's Kappa test. RESULTS: The median parasite density by qPCR was 292 p/µL of blood [IQR (49.7-1137)]. Using qPCR as the reference diagnostic test, the sensitivities of microscopy, RDT and uRDT were respectively [55.7% (95% CI 47.6-63.6)], [81.7% (95%CI 74.7-87.3)] and [88% (95% CI 81.9-92.6)]. The specificities of the tests were calculated at 98.5% (95% CI 96.6-99.5), 95.2% (95% CI 92.5-97.2) and 94.4% (95% CI 91.4-96.6) for microscopy, RDT and uRDT, respectively. The agreement between qPCR and uRDT was almost perfect (Kappa = 0.82). For parasite density (qPCR) below 100 p/µL, the sensitivity of RDT was 62% (95% CI 47.1-75.3) compared to 68% (95% CI 53.3-80.4) for uRDT. Between 100 and 200 p/µL, the sensitivity of RDT was higher, but still lower compared to uRDT: 89.4% (95% CI 66.8-98.7) for RDT versus 100% (95% CI 82.3-100) for uRDT. In both cases, microscopy was lower, with 20% (95% CI 10-33.7) and 47.3% (95% CI 24.4-71.1) respectively. CONCLUSIONS: uRDT has the potential to improve malaria management in pregnant women as it has been found to be slightly more sensitive than RDT in the detection of malaria in pregnant women but the difference was not significant. Microscopy has a more limited value for the diagnosis of malaria during the pregnancy, because of its lower sensitivity.

Variation in neutrophil levels and artemisinin-based combination therapy efficacy in West-Africa.

INTRODUCTION: Polymorphonuclear neutrophils (PMN) are involved in pathogen clearance by phagocytosis. However, the role of PMNs in the efficacy of artemisinin-based combination therapy (ACT) is poorly understood. METHODOLOGY: In a prospective longitudinal in vivo study, neutrophil rates were compared with malaria carriage after treatment with different ACTs: Artemether - lumefantrine (AL), Artesunate - amodiaquine (ASAQ), Dihydroartemisinin - piperaquine (DP) or Pyronaridine artesunate (PA). The study cases were classified as having neutropenia, normal neutrophil levels or neutrophilia depending on the level of neutrophils in the blood. This study included 3148 patients and was analyzed using R. RESULTS: On day 7, only four patients in the neutropenia group and treated with AL had a malaria positive blood smear based on microscopy. On day 28, the rate of recurrent parasitemia in the AL arm was significantly higher in neutropenia patients (50.9%) than in patients with normal rates of neutrophils (43.1%) or in those with neutrophilia (6.0%) (p < 0.001). In ASAQ arm, the rate of recurrent Plasmodium falciparum parasitemia was 58.8% in the neutropenia group versus 29.4% in patients with normal rates of neutrophils and 11.8% in patients with neutrophilia (p < 0.001). No patient treated with DP with normal neutrophil counts or neutrophilia was carrying malaria parasites on day 28. Among the 15 patients with parasitemia on day 28 in the PA arm, 11 (73.33%) had neutropenia while 4 (26.67%) had a normal neutrophil count (p < 0.001). CONCLUSIONS: Patients with neutropenia had higher rates of recurrent P. falciparum parasitemia after ACT.

Creation of a non-Western humanized gnotobiotic mouse model through the transplantation of rural African fecal microbiota.

IMPORTANCE: There is increasing evidence that microbes residing within the intestines (gut microbiota) play important roles in the well-being of humans. Yet, there are considerable challenges in determining the specific role of gut microbiota in human diseases owing to the complexity of diverse internal and environmental factors that can contribute to diseases. Mice devoid of all microorganisms (germ-free mice) can be colonized with human stool samples to examine the specific contribution of the gut microbiota to a disease. These approaches have been primarily focused on stool samples obtained from individuals in Western countries. Thus, there is limited understanding as to whether the same methods used to colonize germ-free mice with stool from Western individuals would apply to the colonization of germ-free mice with stool from non-Western individuals. Here, we report the results from colonizing germ-free mice with stool samples of Malian children.

Efficacy and safety of pyronaridine-artesunate (PYRAMAX) for the treatment of P. falciparum uncomplicated malaria in African pregnant women (PYRAPREG): study protocol for a phase 3, non-inferiority, randomised open-label clinical trial.

INTRODUCTION: Malaria infection during pregnancy increases the risk of low birth weight and infant mortality and should be prevented and treated. Artemisinin-based combination treatments are generally well tolerated, safe and effective; the most used being artemether-lumefantrine (AL) and dihydroartemisinin-piperaquine (DP). Pyronaridine-artesunate (PA) is a new artemisinin-based combination. The main objective of this study is to determine the efficacy and safety of PA versus AL or DP when administered to pregnant women with confirmed Plasmodium falciparum infection in the second or third trimester. The primary hypothesis is the pairwise non-inferiority of PA as compared with either AL or DP. METHODS AND ANALYSIS: A phase 3, non-inferiority, randomised, open-label clinical trial to determine the safety and efficacy of AL, DP and PA in pregnant women with malaria in five sub-Saharan, malaria-endemic countries (Burkina Faso, Democratic Republic of the Congo, Mali, Mozambique and the Gambia). A total of 1875 pregnant women will be randomised to one of the treatment arms. Women will be actively monitored until Day 63 post-treatment, at delivery and 4-6 weeks after delivery, and infants' health will be checked on their first birthday. The primary endpoint is the PCR-adjusted rate of adequate clinical and parasitological response at Day 42 in the per-protocol population. ETHICS AND DISSEMINATION: This protocol has been approved by the Ethics Committee for Health Research in Burkina Faso, the National Health Ethics Committee in the Democratic Republic of Congo, the Ethics Committee of the Faculty of Medicine and Odontostomatology/Faculty of Pharmacy in Mali, the Gambia Government/MRCG Joint Ethics Committee and the National Bioethics Committee for Health in Mozambique. Written informed consent will be obtained from each individual prior to her participation in the study. The results will be published in peer-reviewed open access journals and presented at (inter)national conferences and meetings. TRIAL REGISTRATION NUMBER: PACTR202011812241529.

Accumulation of Neutrophil Phagocytic Antibody Features Tracks With Naturally Acquired Immunity Against Malaria in Children.

BACKGROUND: Studies have demonstrated the protective role of antibodies against malaria. Young children are known to be particularly vulnerable to malaria, pointing to the evolution of naturally acquired clinical immunity over time. However, whether changes in antibody functionality track with the acquisition of naturally acquired malaria immunity remains incompletely understood. METHODS: Using systems serology, we characterized sporozoite- and merozoite-specific antibody profiles of uninfected Malian children before the malaria season who differed in their ability to control parasitemia and fever following Plasmodium falciparum (Pf) infection. We then assessed the contributions of individual traits to overall clinical outcomes, focusing on the immunodominant sporozoite CSP and merozoite AMA1 and MSP1 antigens. RESULTS: Humoral immunity evolved with age, with an expansion of both magnitude and functional quality, particularly within blood-stage phagocytic antibody activity. Moreover, concerning clinical outcomes postinfection, protected children had higher antibody-dependent neutrophil activity along with higher levels of MSP1-specific IgG3 and IgA and CSP-specific IgG3 and IgG4 prior to the malaria season. CONCLUSIONS: These data point to the natural evolution of functional humoral immunity to Pf with age and highlight particular antibody Fc-effector profiles associated with the control of malaria in children, providing clues for the design of next-generation vaccines or therapeutics.

Effects of proactive vs fixed community health care delivery on child health and access to care: a cluster randomised trial secondary endpoint analysis.

Background: Professional community health workers (CHWs) can help achieve universal health coverage, although evidence gaps remain on how to optimise CHW service delivery. We conducted an unblinded, parallel, cluster randomised trial in rural Mali to determine whether proactive CHW delivery reduced mortality and improved access to health care among children under five years, compared to passive delivery. Here we report the secondary access endpoints. Methods: Beginning from 26-28 February 2017, 137 village-clusters were offered care by CHWs embedded in communities who were trained, paid, supervised, and integrated into a reinforced public-sector health system that did not charge user fees. Clusters were randomised (stratified on primary health centre catchment and distance) to care during CHWs during door-to-door home visits (intervention) or based at a fixed village site (control). We measured outcomes at baseline, 12-, 24-, and 36-month time points with surveys administered to all resident women aged 15-49 years. We used logistic regression with cluster-level random effects to estimate intention-to-treat and per-protocol effects over time on prompt (24-hour) treatment within the health sector. Results: Follow-up surveys between February 2018 and April 2020 generated 20 105 child-year observations. Across arms, prompt health sector treatment more than doubled compared to baseline. At 12 months, children in intervention clusters had 22% higher odds of receiving prompt health sector treatment than those in control (cluster-specific adjusted odds ratio (aOR) = 1.22; 95% confidence interval (CI) = 1.06, 1.41, P = 0.005), or 4.7 percentage points higher (adjusted risk difference (aRD) = 0.047; 95% CI = 0.014, 0.080). We found no evidence of an effect at 24 or 36 months. Conclusions: CHW-led health system redesign likely drove the 2-fold increase in rapid child access to care. In this context, proactive home visits further improved early access during the first year but waned afterwards. Registration: ClinicalTrials.gov NCT02694055.

Neither the African-Centric S47 Nor P72 Variant of TP53 Is Associated With Reduced Risk of Febrile Malaria in a Malian Cohort Study.

BACKGROUND: TP53 has been shown to play a role in inflammatory processes, including malaria. We previously found that p53 attenuates parasite-induced inflammation and predicts clinical protection to Plasmodium falciparum infection in Malian children. Here, we investigated whether p53 codon 47 and 72 polymorphisms are associated with differential risk of P. falciparum infection and uncomplicated malaria in a prospective cohort study of malaria immunity. METHODS: p53 codon 47 and 72 polymorphisms were determined by sequencing TP53 exon 4 in 631 Malian children and adults enrolled in the Kalifabougou cohort study. The effects of these polymorphisms on the prospective risk of febrile malaria, incident parasitemia, and time to fever after incident parasitemia over 6 months of intense malaria transmission were assessed using Cox proportional hazards models. RESULTS: Confounders of malaria risk, including age and hemoglobin S or C, were similar between individuals with or without p53 S47 and R72 polymorphisms. Relative to their respective common variants, neither S47 nor R72 was associated with differences in prospective risk of febrile malaria, incident parasitemia, or febrile malaria after parasitemia. CONCLUSIONS: These findings indicate that p53 codon 47 and 72 polymorphisms are not associated with protection against incident P. falciparum parasitemia or uncomplicated febrile malaria.

Effect of community health worker home visits on antenatal care and institutional delivery: an analysis of secondary outcomes from a cluster randomised trial in Mali.

INTRODUCTION: Though community health workers (CHWs) have improved access to antenatal care (ANC) and institutional delivery in different settings, it is unclear what package and delivery strategy maximises impact. METHODS: This study reports a secondary aim of the Proactive Community Case Management cluster randomised trial, conducted between December 2016 and April 2020 in Mali. It evaluated whether proactive home visits can improve ANC access at a population level compared with passive site-based care. 137 unique village clusters, covering the entire study area, were stratified by health catchment area and distance to the nearest primary health centre. Within each stratum, clusters were randomly assigned to intervention or control arm. CHWs in intervention clusters proactively visited all homes to provide care. In the control clusters, CHWs provided the same services at their fixed community health post to care-seeking patients. Pregnant women 15-49 years old were enrolled in a series of community-based and facility-based visits. We analysed individual-level annual survey data from baseline and 24-month and 36-month follow-up for the secondary outcomes of ANC and institutional delivery, complemented with CHW monitoring data during the trial period. We compared outcomes between: (1) the intervention and control arms, and (2) the intervention period and baseline. RESULTS: With 2576 and 2536 pregnancies from 66 and 65 clusters in the intervention and control arms, respectively, the estimated risk ratios for receiving any ANC was 1.05 (95% CI 1.02 to 1.07), four or more ANC visits was 1.25 (95% CI 1.08 to 1.43) and ANC initiated in the first trimester was 1.11 (95% CI 1.02 to 1.19), relative to the controls; no differences in institutional delivery were found. However, both arms achieved large improvements in institutional delivery, compared with baseline. Monitoring data show that 19% and 2% of registered pregnancies received at least eight ANC contacts in the intervention and control arms, respectively. Six clusters, three from each arm had to be dropped in the last 2 years of the trial. CONCLUSIONS: Proactive home visits increased ANC and the number of antenatal contacts at the clinic and community levels. ANC and institutional delivery can be increased when provided without fees from professional CHWs in upgraded primary care clinics. TRIAL REGISTRATION NUMBER: NCT02694055.

Evidence for exposure dependent carriage of malaria parasites across the dry season: modelling analysis of longitudinal data.

BACKGROUND: In malaria endemic regions, transmission of Plasmodium falciparum parasites is often seasonal with very low transmission during the dry season and high transmission in the wet season. Parasites survive the dry season within some individuals who experience prolonged carriage of parasites and are thought to 'seed' infection in the next transmission season. METHODS: Dry season carriers and their role in the subsequent transmission season are characterized using a combination of mathematical simulations and data analysis of previously described data from a longitudinal study in Mali of individuals aged 3 months-12 years (n = 579). RESULTS: Simulating the life-history of individuals experiencing repeated exposure to infection predicts that dry season carriage is more likely in the oldest, most exposed and most immune individuals. This hypothesis is supported by the data from Mali, which shows that carriers are significantly older, experience a higher biting rate at the beginning of the transmission season and develop clinical malaria later than non-carriers. Further, since the most exposed individuals in a community are most likely to be dry season carriers, this is predicted to enable a more than twofold faster spread of parasites into the mosquito population at the start of the subsequent wet season. CONCLUSIONS: Carriage of malaria parasites over the months-long dry season in Mali is most likely in the older, more exposed and more immune children. These children may act as super-spreaders facilitating the fast spread of parasites at the beginning of the next transmission season.